Demand fuel regulator



Oct. 6, 1964 H. 'r. M. RICE 3,151,627

DEMAND FUEL REGULATOR Filed May 8, 1961 Rio, 1 T- 2 Sheets-Sheet l INVENTOR Her/2y 7:111. R/cs Oct. 6, 1964 H. T. M. RICE DEMAND FUEL REGULATOR 2 Sheets-Sheet 2 Filed May 8, 1961 INVENTOR. HENRY 7: M. 12/65 flrraZ/VEY.

United States Patent 3,151,627 EMAND FUEL REGULATOR Henry T. M. Rice, San Gabriel, Califu, assiguor to Ohlsson 8: Rice, Inc., Los Angeles, Callh, a corporation of California Filed May 8, 1961, Ser. No. 188,647 15 Claims. (Cl. 137-4%) The present invention relates to apparatus for supplying fuel to internal combustion engines, and more particularly to regulators for controlling the passage of fuel to the carburetors of such engines.

An object of the invention is to provide a fuel regulator capable of supplying fuel at substantially a constant pressure regardless of the hydrostatic head of fuel in the fuel tank. The pressure at which fuel is supplied remains substantially constant regardless of centrifugal or acceleration forces acting on the engine, or the specific position of the engine, which may even be inverted from its normal position of operation.

Another object of the invention is to provide a fuel regulator capable of supplying fuel at a substantially constant pressure, which is relatively small and compact, and which has a high degree of sensitivity due, to a large extent, to the minimizing of friction in the relatively moving parts.

A further object of the invention is to provide a fuelregulator capable of supplying fuel at a substantially constant pressure, which is economical to manufacture, and which has a long, useful life.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a side elevational view, with parts shown in longitudinal section, of a carburetor and demand fuel regulator embodying the invention;

FIG. 2 is a section taken along the line 22 on PEG. 1;

FIG. 3 is a cross-section taken along the line 3-3 on FIG. 2;

FIG. 4 is an enlarged section taken generally along the line 44 on FIG. 2, parts being shown in side elevation;

FIG. 5 is an enlarged cross-section taken along the line 55 on FIG. 2, parts being shown in side elevation.

The demand fuel regulator A illustrated in the drawings is adapted to receive fuel through a suitable inlet line 1% and to deliver the fuel to a carburetor B suitably connected with the intake C of an internal combustion engine. As disclosed, the carburetor B includes a venturi 11 having a throat portion 12 in which a throttle plate 13 is pivotally mounted, the plate being attached to a rod 14 pivoted in the body 15 of the carburetor. The rod 14 and throttle plate 13 are suitably supported in the body 15, as by means of a flange 16 on the rod engaging the exterior of the body, being held yieldably thereagainst by a coil spring 17 engaging the opposite end of the body, and suitably secured to the rod.

Air from a suitable inlet line 18 passes into the air inlet 19 of the carburetor body, which is controlled by a suitable cholze plate 26 secured to a rod or pin 21 pivotally mounted in the body 15 and having a choke lever 22 attached thereto, for determining the position of the choke plate in the inlet air passage 19. Air flowing through the inlet 19 past the choke flows through the throat 12 of the venturi, creating a suction therewithin and drawing fuel thereinto for admixture with the air for delivery to the engine cylinder or cylinders. The fuel flows through a carburetor jet 23 threadedly mounted in a threaded bore 24 in the carburetor body 15 and extending into a recess 25 in the throttle plate 13. The threaded bore is closed by a screw plug 26 which also serves to secure the case or housing 27 or" the demand fuel regulator apparatus A to the carburetor body B.

Fuel, such as gasoline, from a suitable tank (not shown), or other supply, flows through the fuel inlet line 19 into an inlet passage 28 in the diaphragm case 27. From this inlet passage, the fuel can flow past a valve element 29, such as a ball, into a shallow chamber 3i from where it-fiows through an outlet 31 in the housing communicating with a passage 32 in the carburetor body 15 that discharges into the threaded bore 24 of the carburetor, the fuel llowing through the carburetor jet passage 33 and into the venturi throat 12. Flow of fluid from the regulator outlet 31 is controlled by an adjusting needle valve 34 threadedly secured in the carburetor body 15 and extending across the passage 32. A suitable com pression spring 35 bears against a knurled head 36 of the needle valve and against the carburetor body 15 to retain the needle valve in its position of adjustment across the inlet passage 32..

The screw plug 25 engages the diaphragm case 27 and holds the latter in sealed relation to the carburetor body 15, a suitable gasket 37 being interposed between the case and body to prevent leakage therebetween. The diaphragm case 27 has a rubber or rubber-like diaphragm 38 extending across its chamber 30, which is held in place by a cover plate 39 suitably secured to the case by a plurality of screws 49. One side of the flexible or elastic diaphragm 33 is open to atmosphere through a hole 41 extending through the cover plate 39. Bearing against the other side of the diaphragm 38 and disposed in the regulator chamber 36 is a diaphragm plate 4-2 extending substantially across the full diameter of the chamber, but having its outer margin 43 inclined in an outward direction away from the diaphragm 38, so as to permit the portion of the diaphragm between its outer point of engagement with the plate 42 and the case 27 to flex as the result of operation of the regulator.

The mid-portion 52a of the diaphragm plate 42 bears against a curved or concave portion 44a of one arm 44 of a lever 45, the inner portion of this arm merging into a saddle portion 46 of the lever disposed around and in engagement with a bushing 47 rotatably mounted on a fulcrum pin 48 extending across a cavity in the diaphragm case 27 below the chamber 3%, the pin being received within transverse grooves 50 in the case 27 and being firmly secured therewithin, as by peening over the case material 51 on opposite sides of the grooves 59 against the end portion 52 of the pin 48. The saddle portion 45 of the lever 45 merges into another lever arm portion 53 which bears against the ball valve element 29, which is movable downwardly into engagement with a companion valve seat 54. surrounding the inlet passage 28. The valve element 29 is disposed within a confining counterbore 5'5 in the case 27 below the cavity 4-9 to prevent the ball from being disengaged from the lower arm 53.

The partial vacuum developed by air passing through the venturi throat 12, which creates a corresponding vacuum in the diaphragm chamber 30, tends to result in inward movement of the diaphragm 38 and plate 42 to rock the lever 4-6 and bushing about the axis of the fulcrum pin 48, and thereby allow the ball 29 to be removed from its companion seat 54, permitting fuel to flow into the diaphragm chamber 33 and through the outlet 31 to the needle valve 34, flowing around the latter and through the carburetor jet 23 into the venturi portion 12 of the carburetor. spring 66 of generally U-shape. The opposed arms 61 of the spring are arranged on opposite sides of the plane of movement of lever 45 and engage the underside of the bushing 47, with the free ends 62 of the arms contacting a roller 63 extending transversely of the arms and bearing against the bottom 64 of the diaphragm case 27. The

Such movement is resisted by a flat leaf outer ends 62 of the arms are bent slightly around the V roller 63 to ensure against loss of contact or disassembly portion 67 of the U-shaped leaf spring 6% bears upon the lever arm 53 substantially opposite the ball 29, the movement of the spring to the left, as seen in FIG. 4, being limited by an upwardly projecting stop hook 68 formed on the lever arm.

The leaf spring 66} has the free ends 62 of its arms in contact with the anti-friction roller as, the intermediate portion of the arms contacting the fulcrum bushing 47 and its transverse or web portion 67 engaging the arm 53 of the lever, the spring 60 being under tension so that it urges the ball 29 into engagement with its seat 54 to prevent flow of fuel through the passage 28 and into the chamber 30 of the regulator. A. Assuming suction or partial vacuum to be present in the diaphragm chamber, the diaphragm plate 42 and the elastic diaphragm 38 are moved inwardly by the predominating atmospheric pressure, causing the lever and bushing 47 to rock about the axis of the fixed fulcrum pin 48, and against the force of the spring fill, to remove the arm 53 of the lever from contact with the ball 29 and allowing the fuel to unseat the ball and flow around the latter into the diaphragm case 27, filling the latter and then flowing outwardly through the outlet 31 into the needle valve passage 32 for continued flowing around the needle valve 34 and through the carburetor jet 23 into the venturi 12.

The regulator will maintain the fuel in the chamber 39 and on the high pressure side of the needle valve 34 substantially constant. If the suction in the chamber 36 increases momentarily, as, for example, by opening the throttle plate 13, the diaphragm plate 42 and diaphragm 38 move inwardly to a greater extent, to rock the lever 45 and bushing 47 about the fulcrum pin 48, and against the force of the spring 60, to a greater extent, allowing the ball 29 to move to a greater extent from its valve seat 54, thereby allowing fuel to flow into the chamber at a greater pressure, decreasing the vacuum in the chamher 3%, whereupon the lever mechanism 38, 42, 45 will offset the spring force to a lesser extent, allowing the.

lower arm 53 to move in the opposite direction and close the diaphragm chamber 30 were to increase, as by virtue of a lesser demand for fuel by the engine, then the diaphragm 38' and diaphragm plate42 would move in an outward direction allowing the spring 60 to shift the valve 29 toward a closed position, thereby decreasing the flow of fuel into the. diaphragm chamber 30 and resulting in 'a decrease in pressure therein. .Accordingly, the pres sure of fueliin' the diaphragmxihamber 30'is maintained at a substantially constant pressure, since if'the fuel flow 2' the valve to a greater extent. 'Accordingly, a constant pressure is maintained on the high pressure side of the carburetor'needle adjusting valve34, and such pressure is; rmaintainedregardless of changes in the hydrostatic the lever 45.

' the valve partly. On the other hand, if the pressure in V t head of fuel supply, centrifugal forces, acceleration forces or inverting of the engine.

The chamber 3%? containing the diaphragm is made shallow and compact'so that the head of fuel in the diaphragm case 27 is relatively small, and cannot cause ad-' Verse action of parts due to sudden accelerations or de celerations, the action of centrifugal force, and the like. Regardless of the position of the engine and'its attached carburetor B and fuel regulator A,,the mechanism operates to maintain the pressure in the regulator chamber 3% substantially constant. The mechanism is quick-acting, and automatically compensates for different conditions that are encountered. The quick action is due to a great extent to the making of the chamber shallow, as has been noted above, and also due to the minimiz ng of friction in the relatively moving parts. With respect to friction, it is to be noted that the saddle portion 46 of the operating lever 45 engages the bushing 47 at one side thereof, and that the spring arms 61 engage the bushing on the diametrically opposite side thereof. The force imposed by the saddle 46 on the bushing 47 is substantially equal to the force imposed by the spring arms 61 on the bushing, so that the bushing practically floats. That such forces are equal and opposite is due to the fact that'the moment arm of the lever 45 from the fulcrum pin 48 to the point of contact of the curved portion with the diaphragm plate 42 is substantially equal to the moment arm of the spring arms 61 from their points of contact with the bushing 47 to the roller 63. Similarly, the point of contact of the intermediate portion 67 of the spring with the other arm 53 of the lever is substantially opposite the point of contact of the ball valve element 29 with such lever arm. Accordingly, the force imposed on the bushing 47 by the lever 45 is substantially equal to the 1 force imposed by the spring 60 on the bushing, which,

therefore, causes the bushing to float on the pin 48,

there being substantially no friction therebetween. Moreover, during movement of the lever and spring, the end portions 62 of the spring roll on the roller 63, so that there is no sliding friction between the parts. As a result,

the moving parts of the apparatus are sensitive in their operation, and respond rapidly to changes in forces, and directionof such forces, to insure the maintenance of the pressure of the fuel filling the chamber 30 constant.

The regulator A functions as well with the engine in an upright position as when it is inverted. As noted above, the pressures remain substantially constant in the regulator chamber 38 and outlet 31 regardless of the hydrostatic head of fuel in the fuel tank. Assuming the engine to be in the upright condition, a certain pressure is necessary to raise the ball 25? fromits seat'54 because of the weight of the ball itself. Such pressure, however, is offset to some extent by the force of gravity acting on To the weight of the lever 45 must be added the weight of the diaphragm plate 42 and of a portion of the rubber or rubber-like diaphragm 38 itself. Accordingly, the weight of the ball 29 is made such that it is substantially offset by the resulting weightof the lever 45 (considering both arms 44, 53 of the lever) and the efiective weight of the diaphragm plate 42 and of the diaphragm 38. These latter weights are offsetting 1 the force of the spring 60in urging the ball 29 toward its seat 53; Thus, there is a lesser spring force available for urging the ball 29 toward its seat, which corresponds closely to the weight of the ball itself.

In the event the engine is inverted, then, the weight of' the ball 29 is acting in the opposite direction and is operating against the force of the spring 60, and is assisting the pressure differential causing fuel to flow past the and the rubber diaphragm 38,"which nowsubtract from the spring force, so that a greater resulting spring force is available'for urging the ball .valve 29 to its. seatv54.

5 The Weight of the lever 45, diaphragm plate 42 and diaphragm 38 add to the spring force tending to urge the ball toward its seat, ofisetting the Weight of the ball 29 itself. Substantially the same resulting spring force is available for urging the ball towards its seat when the engine and regulator are inverted, as when the engine and regulator are in their upright position.

It is, accordingly, apparent that a demand fuel regulator has been provided, which Will maintain the supply of fuel at a substantially constant pressure regardless of the hydrostatic head of fuel in the fuel tank, the position of the engine, acceleration forces of any equipment, such as a vehicle, in which the engine may be contained, centrifugal forces, and the like. The regulator is comparatively economical to manufacture. It is compact and has a high degree of sensitivity or accuracy in maintaining the fuel pressure substantially constant.

I claim:

1. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; spring means urging said element into engagement with said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and having a first arm engaging said diaphragm means and a second arm engaging said element; said spring means bearing against said pin and second arm to urge said element into engagement with said seat.

2. In a fuel regulator: a case having a chamber therein provided With inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable With said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and engaging said diaphragm means and element; a spring engaging said fulcrum pin and extending in opposite directions therefrom to provide oppositely directed spring arms; means on said case engaging one of said arms; said other arm engaging said lever to urge said element into engagement with said seat.

3. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable With said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and engaging said diaphragm means and element; a leaf spring engaging said fulcrum pin and extending in opposite directions therefrom to provide oppositely directed spring arms; means on said case engaging one of said arms; said other arm engaging said lever to urge said element into engagement with said seat.

4. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum phi supported in said chamber; a lever pivoted on said pin and engaging said diaphragm means and element; a leaf spring engaging said fulcrum pin and lever to urge said element into engagement with said seat; and a reliable element engaging said case and a free end of said leaf spring.

5. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and having a first arm engaging said diaphragm means and a second arm engaging said element; and a leaf spring engaging said fulcrum pin and having a first arm engaging means on said case and a second arm engaging said 6 second arm of said lever to urge said element toward said seat.

6. In a fuel regulator: a case having a chamber therein provided With inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and having a first arm engaging said diaphragm means and a second arm en aging said element; and a leaf spring engaging said fulcrum pin and having a first arm engaging means on said case and a second arm engaging said second arm of said lever to urge said element toward said seat; said first lever arm and first spring arm being of substantially equal length, and said second spring arm and second lever arm being of substantially equal length.

7. in a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum pin supported in said chamber; a lever pivoted on said pin and having a first arm engaging said diaphragm means and a second arm engaging said element; and a leaf spring engaging said fulcrum pin and having a first arm engaging rneans on said case and a second arm engaging said second arm of said lever to u ge said element toward said seat; the point of engagement of said first lever arm with said diaphragm means being substantially opposite the point of engagement of said first spring arm with said means on said case; the point of engagement of said second lever arm With said element being substantially opposite the point of engagement of said second spring arm with said second lever arm.

8. in a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable With said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and engaging said diaphragm means and element; and a spring engaging said bushing on the opposite side thereof and also engaging said lever to urge said element into engagement with said seat.

9. in a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm means and a second arm engaging said element; and a leaf spring engaging said bushing on the opposite side thereof and having a first arm engaging means on said case and a second arm engaging said second lever arm to urge said element toward said seat.

it). in a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means ecured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable With said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm means and a second arm engaging said element; a leaf spring engaging said bushing on the opposite side thereof and having a first arm and a second arm engaging said second lever arm to urge said element toward said seat; and a roller reliable on said case and engaging said first spring arm.

11. in a fuel regulator: a case having a chamber therein provided With inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing' a valve seat surrounding said inlet passage; a valve element on a eable with said seat; a fulcrum in supb in ported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm means and a second arm engaging. said element; and a leaf spring engaging said bushing on the opposite side thereof and having a first arm engaging means on said case and a second arm engaging said second lever arm to urge said element toward said seat; said first lever arm and first spring arm being of substantially equal'length, and said second spring arm and second lever arm being of substantially equal length.

12. In a ruel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable ith said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a' lever engaging said bushing on one side thereof and having a first arm engaging said dianhragm means and a second arm engaging said element; and a leaf spring engaging said bushing on the opposite side thereof and having a first arm engaging means'on said case ands second arm engaging said second lever arm to urge said element toward said seat; the point of engagement of said first lever arm with said diaphragm means being substantially opposite the point of engagement of said first spring arm with said deans on said case; the point of engagement of said second lever arrn with said element being substantiall opposite the point of engagement of said second spring arm with said second lever arm.

7 13. in a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means secured to said case across said chamber; said case providing a valve seat surrounding said inlet passage; a valve element engageable with said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm means and a second arm engaging said element; a. leaf spring engaging said bushing on the opposite side thereof and having a first arm and a second arm engaging said second lever arm to urge said element toward said seat; and a g roller reliable on said case and engaging said first spring arm; the length of said first lever arm to the point of its engagement with said diaphragm means being substantially equal to the length of said first spring arm to its point of engagement with said roller, and said second spring arm and second lever arm being of substantially equal length.

14. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm means a. S secured to said case across said-chamber; said case provin'ng a valve seat surrounding said inlet passagega valve element cngageable with said seat; a fulcrum pin supported in said chamber; a bushing rotatable on said pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm means and a second arm engaging said element; and a generally 'U-shaped leaf spring having arms disposed on opposite sides of said lever and engaging said bushing on the opposite side thereof; a roller rollable on said case and engaged by end portions of said spring arms; said leaf spring including an intermediate portion interconnecting said spring arms and engaging said second lever arm to urge said element toward said seat.

15. In a fuel regulator: a case having a chamber therein provided with inlet and outlet passages; diaphragm. means secured to said case across said chamber; said case" providing a valve seat surrounding said inletpassage; a valve element engageable with said seat; a fulcrum pin supp rted in said'chamber; a bushing rotatable on said 'pin; a lever engaging said bushing on one side thereof and having a first arm engaging said diaphragm and a second arm engaging said element; a generally U-shaped leaf sp ing having arms disposed on opposite sides of said lever and engaging said bushing on the opposite side thereof; a roller reliable on said case and engaged by end portions of said spring arms; said leaf spring including an intermediate portion interconnecting said spring armstand engaging said second lever arm to urge said element toward said seat; the point of engagement of said first lever arm with said diaphragm 'rneans being substantially opposite the point of engagement of said spring arms with said roller; the point of engagement of said second lever arm with said element being substantially opposite the point of engagement of saidintermediate spring portion with said second lever arm.

References Cited in the file of this patent UNITED STATLS PATENTS Germany Dec. 22, 1941 

1. IN A FUEL REGULATOR: A CASE HAVING A CHAMBER THEREIN PROVIDED WITH INLET AND OUTLET PASSAGES; DIAPHRAGM MEANS SECURED TO SAID CASE ACROSS SAID CHAMBER; SAID CASE PROVIDING A VALVE SEAT SURROUNDING SAID INLET PASSAGE; A VALVE ELEMENT ENGAGEABLE WITH SAID SEAT; SPRING MEANS URGING SAID ELEMENT INTO ENGAGEMENT WITH SAID SEAT; A FULCRUM PIN SUPPORTED IN SAID CHAMBER; A LEVER PIVOTED ON SAID PIN AND HAVING A FIRST ARM ENGAGING SAID DIAPHRAGM MEANS AND A SECOND ARM ENGAGING SAID ELEMENT; SAID SPRING MEANS BEARING AGAINST SAID PIN AND SECOND ARM TO URGE SAID ELEMENT INTO ENGAGEMENT WITH SAID SEAT. 